face: Rename all ChannelFactories to protocol Factories

Base class is ProtocolFactory and implementations are TcpFactory,
UnixStreamFactory, EthernetFactory.

Since Factories are doing more than just creating channels (some can
create faces directly), more general name is more appropriate.

Change-Id: I3d6c2460a1b29e244f8462453720f4e7785893ca
diff --git a/daemon/main.cpp b/daemon/main.cpp
index b8165f8..e971a35 100644
--- a/daemon/main.cpp
+++ b/daemon/main.cpp
@@ -10,10 +10,10 @@
 #include "mgmt/internal-face.hpp"
 #include "mgmt/fib-manager.hpp"
 #include "mgmt/local-control-header-manager.hpp"
-#include "face/tcp-channel-factory.hpp"
+#include "face/tcp-factory.hpp"
 
 #ifdef HAVE_UNIX_SOCKETS
-#include "face/unix-stream-channel-factory.hpp"
+#include "face/unix-stream-factory.hpp"
 #endif
 
 namespace nfd {
@@ -43,12 +43,12 @@
 static Forwarder* g_forwarder;
 static FibManager* g_fibManager;
 static LocalControlHeaderManager* g_localControlHeaderManager;
-static TcpChannelFactory* g_tcpFactory;
+static TcpFactory* g_tcpFactory;
 static shared_ptr<TcpChannel> g_tcpChannel;
 static shared_ptr<InternalFace> g_internalFace;
 
 #ifdef HAVE_UNIX_SOCKETS
-static UnixStreamChannelFactory* g_unixFactory;
+static UnixStreamFactory* g_unixFactory;
 static shared_ptr<UnixStreamChannel> g_unixChannel;
 #endif
 
@@ -171,7 +171,7 @@
 void
 initializeTcp()
 {
-  g_tcpFactory = new TcpChannelFactory();
+  g_tcpFactory = new TcpFactory();
   g_tcpChannel = g_tcpFactory->create(g_options.m_tcpListen.first,
                                       g_options.m_tcpListen.second);
   g_tcpChannel->listen(
@@ -190,7 +190,7 @@
 void
 initializeUnix()
 {
-  g_unixFactory = new UnixStreamChannelFactory();
+  g_unixFactory = new UnixStreamFactory();
   g_unixChannel = g_unixFactory->create(g_options.m_unixListen);
 
   g_unixChannel->listen(